Spratelloides delicatulus (Bennett, 1831)
(Blue-Backed Sprat, Blue Sprat)
(Note: The photos of this fish in the 1st and 2nd printings of Hawaii's Fishes and the Ultimate Guide to Hawaiian Reef Fishes incorrectly show Hawaiian Silversides and vice versa)
These small elongate silvery fish are seen over shallow reef flats in fast-moving schools but also resting in shaded areas such as under piers. They are bluish above and silvery white below. There are two dark marks at the base of the tail, difficult to see in the field. The far more abundant Hawaiian Silverside is similar but has larger eyes and two well-separated dorsal fins. To about 3.5 in. Indo-Pacific. Photo: Ho'okena, Hawai'i.